Temperature control device for two-stage mixed PID (Proportion Integration Differentiation) control

Abstract

The utility model discloses a two-stage mixed PID (Proportion Integration Differentiation) controlled temperature control device, and relates to the technical field of temperature control. The system comprises a microprocessor, a first thermoelectric refrigerating unit (1), a first temperature sensor (2), a digital PID controller, a second thermoelectric refrigerating unit (3), a second temperature sensor (4) and an analog PID controller, and the first thermoelectric refrigerating unit, the first temperature sensor and the digital PID controller form a first-stage thermoelectric refrigerating unit TEC hot end temperature control unit. The second thermoelectric refrigerating unit, the second temperature sensor and the simulation PID controller form a second-stage laser diode temperature control unit, the microprocessor firstly starts a first-stage thermoelectric refrigerating unit TEC hot end temperature control unit to stabilize the hot end temperature of the second thermoelectric refrigerating unit at a preset value, and then starts the second-stage laser diode temperature control unit to stabilize the hot end temperature of the second thermoelectric refrigerating unit at the preset value; the temperature of the laser diode is accurately controlled at the working temperature, and high temperature control precision and good stability are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to temperature control technical field especially relates to a two -stage hybrid PID control's temperature control device. BACKGROUND

[0002] As a widely used light source in modern optoelectronic systems, laser diodes have significant advantages over traditional gas and solid-state lasers, such as small size, light weight, high electro-optical conversion efficiency, and direct electrical modulation. The electro-optical conversion efficiency of laser diodes is typically between 30% and 50%, which is much higher than that of gas and traditional solid-state lasers, significantly reducing system energy consumption. Laser diodes also have long service life, low cost, and wide wavelength coverage, making them the ideal choice for optoelectronic systems.

[0003] However, laser diodes also have significant limitations, the most important of which is their extreme sensitivity to temperature changes. The typical temperature coefficient of the output wavelength of a laser diode is about 0.1-0.3 nm / ℃, which means that even a temperature fluctuation of only 0.1℃ can cause a wavelength shift of 10-30 pm. In fiber Bragg grating sensing applications, a wavelength shift of 1 pm can correspond to a strain of about 1 με or a temperature change of 0.1℃, so in these applications, the wavelength stability of the laser source is usually required to be better than ±1 pm, i.e., the temperature control accuracy of the laser diode needs to be better than ±0.01℃. Temperature fluctuations also affect the output power stability of the laser diode, cause output laser mode jumps, reduce spectral purity, and accelerate device aging.

[0004] Currently, laser diode temperature control systems typically use a single-stage thermoelectric cooler (TEC) structure combined with a single digital or analog PID control method. The temperature control accuracy of conventional single-stage TEC systems is usually ±0.1℃ in practical applications, which cannot meet the requirements of high-precision applications, mainly due to the direct conduction of TEC hot-end temperature fluctuations to the cold end. A single control strategy also cannot balance the system response speed and stability. Increasing the system response speed often introduces temperature overshoot and oscillation, while increasing the system stability reduces the response ability to external disturbances. When facing large-scale environmental temperature changes, the temperature control accuracy of existing systems will deteriorate significantly, and the long-term wavelength stability of the laser diode cannot be guaranteed.

[0005] Therefore, low temperature control accuracy and poor stability are technical problems that need to be solved. INVENTION CONTENTS

[0006] The utility model provides a two -stage hybrid PID control's temperature control device, solves the technical problem of low temperature control accuracy and poor stability.

[0007] To solve the above technical problems, the technical solution adopted by the utility model is as follows:

[0008] A temperature control device with two-stage hybrid PID control includes a microprocessor, a first thermoelectric cooler, a first temperature sensor, a digital PID controller, a second thermoelectric cooler, a second temperature sensor, and an analog PID controller. The hot end of the second thermoelectric cooler is in contact with and connected to the cold end of the first thermoelectric cooler, and the cold end of the second thermoelectric cooler is used to contact and connect to a laser diode. The microprocessor is electrically connected to the digital PID controller and the analog PID controller. The first temperature sensor is electrically connected to the digital PID controller, the digital PID controller is electrically connected to the first thermoelectric cooler, the second temperature sensor is electrically connected to the analog PID controller, and the analog PID controller is electrically connected to the second thermoelectric cooler. The first temperature sensor is used to monitor and obtain the temperature of the hot end of the second thermoelectric cooler and inform the digital PID controller, and the second temperature sensor is used to monitor and obtain the temperature of the laser diode and inform the analog PID controller.

[0009] A further technical solution is that the first temperature sensor is in contact with and fixedly connected to the hot end of the second thermoelectric cooler.

[0010] A further technical solution is that the second temperature sensor is used to contact and be fixedly connected to the laser diode.

[0011] A further technical solution includes a radiator, which is used to contact and connect the hot end of the first thermoelectric cooler to the radiator.

[0012] A further technical solution includes a laser diode, with the cold end of the second thermoelectric cooler in contact with and connected to the laser diode, and the second temperature sensor in contact with and connected to the laser diode.

[0013] A further technical solution includes an insulation layer, which is then wrapped and fixed onto the first thermoelectric cooler, the first temperature sensor, the second thermoelectric cooler, and the second temperature sensor.

[0014] The beneficial effects of adopting the above technical solution are as follows:

[0015] The utility model provides a two -stage hybrid PID control's temperature control device, including microprocessor, first thermoelectric refrigerator, first temperature sensor, digital PID controller, second thermoelectric refrigerator, second temperature sensor and analog PID controller, and the hot end of second thermoelectric refrigerator is contacted with the cold end of first thermoelectric refrigerator and is connected together, and the cold end of second thermoelectric refrigerator is used for contacting with laser diode and is connected together, microprocessor is electrically connected with digital PID controller, microprocessor is electrically connected with analog PID controller, first temperature sensor is electrically connected with digital PID controller, digital PID controller is electrically connected with first thermoelectric refrigerator, second temperature sensor is electrically connected with analog PID controller, analog PID controller is electrically connected with second thermoelectric refrigerator, and first temperature sensor is used for monitoring obtains the hot end temperature of second thermoelectric refrigerator and informs digital PID controller, and second temperature sensor is used for monitoring obtains the temperature of laser diode and informs analog PID controller, first thermoelectric refrigerator, first temperature sensor and digital PID controller form one -level thermoelectric refrigerator TEC hot end temperature control unit, and second thermoelectric refrigerator, second temperature sensor and analog PID controller form two -stage laser diode temperature control unit, and microprocessor starts one -level thermoelectric refrigerator TEC hot end temperature control unit first, and the hot end temperature of second thermoelectric refrigerator is stabilized at the preset value, then starts two -stage laser diode temperature control unit, and the temperature of laser diode is accurately controlled at the working temperature, and high precision, good stability are realized to temperature control.

[0016] See the part of specific embodiment description. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the structure diagram of the utility model;

[0018] Figure 2 It is the principle block diagram of the utility model.

[0019] Among them: 1 first thermoelectric refrigerator, 2 first temperature sensor, 3 second thermoelectric refrigerator, 4 second temperature sensor, 5 radiator, 6 laser diode, 7 heat preservation layer. CONCRETE EMBODIMENT

[0020] The purpose of the application is to provide a two -stage hybrid PID control's temperature control device, especially applicable to laser diode, and high -precision temperature control is realized.

[0021] Through the cascade type thermoelectric refrigerator TEC structure and hybrid PID control strategy, the high-precision control of laser diode temperature is realized, and the demand of optical system requirement is met to the wavelength stability.The device can stabilize the temperature of laser diode in the range of ±0.005 DEG C.

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] like Figure 1 and Figure 2 As shown, this utility model discloses a two-stage hybrid PID control temperature control device, including a microprocessor, a first-stage thermoelectric cooler (TEC) hot-end temperature control unit, and a second-stage laser diode temperature control unit. The first-stage thermoelectric cooler (TEC) hot-end temperature control unit includes a first thermoelectric cooler 1, a first temperature sensor 2, and a digital PID controller. The second-stage laser diode temperature control unit includes a second thermoelectric cooler 3, a second temperature sensor 4, and an analog PID controller.

[0025] like Figure 1 As shown, the hot end of the second thermoelectric cooler 3 is in contact with and fixedly connected to the cold end of the first thermoelectric cooler 1, the first temperature sensor 2 is in contact with and fixedly connected to the hot end of the second thermoelectric cooler 3, the cold end of the second thermoelectric cooler 3 is used to contact and fixedly connect to the laser diode, and the second temperature sensor 4 is used to contact and fixedly connect to the laser diode.

[0026] like Figure 2 As shown, the microprocessor is electrically connected to the digital PID controller, the microprocessor is electrically connected to the analog PID controller, the first temperature sensor 2 is electrically connected to the digital PID controller, the digital PID controller is electrically connected to the first thermoelectric cooler 1, the second temperature sensor 4 is electrically connected to the analog PID controller, and the analog PID controller is electrically connected to the second thermoelectric cooler 3.

[0027] Instructions for use:

[0028] like Figure 1 As shown, the hot end of the first thermoelectric cooler 1 is in contact with and fixedly connected to the radiator 5, the cold end of the second thermoelectric cooler 3 is in contact with and fixedly connected to the laser diode 6, and the second temperature sensor 4 is in contact with and fixedly connected to the laser diode 6.

[0029] The first thermoelectric cooler 1 is connected between the second thermoelectric cooler 3 and the radiator 5, and the hot end of the second thermoelectric cooler 3 and the cold end of the first thermoelectric cooler 1 form a heat conduction path.

[0030] The first temperature sensor 2 is used to monitor and obtain the hot end temperature of the second thermoelectric cooler 3 and transmit the temperature signal to the digital PID controller.

[0031] The second thermoelectric cooler 3 is installed close to the laser diode 6.

[0032] The second temperature sensor 4 is closely attached to the laser diode 6 and is used to accurately monitor the temperature of the laser diode 6.

[0033] The insulation layer 7 is wrapped and fixed onto the first thermoelectric cooler 1, the first temperature sensor 2, the second thermoelectric cooler 3, the second temperature sensor 4, the radiator 5, and the laser diode 6.

[0034] The entire device adopts a thermal insulation design to ensure that heat exchange between the device and the external environment is minimized.

[0035] Both digital PID controllers and analog PID controllers are controlled and set via microprocessors.

[0036] The primary thermoelectric cooler (TEC) hot-end temperature control unit is controlled by a digital PID controller.

[0037] The digital PID controller receives the feedback signal from the first temperature sensor 2 and outputs a control signal to the first thermoelectric cooler 1.

[0038] The digital PID controller obtains and outputs control signals to the first thermoelectric cooler 1 based on the preset temperature value of the microprocessor and the actual temperature measurement value fed back by the first temperature sensor 2, according to the existing data mapping table, thereby achieving stable control of the hot end temperature of the second thermoelectric cooler 3.

[0039] The secondary laser diode temperature control unit uses analog PID control.

[0040] The analog PID controller receives the feedback signal from the second temperature sensor 4 and outputs a control signal to the second thermoelectric cooler 3.

[0041] The analog PID controller obtains the temperature error based on the preset temperature value of the microprocessor and the actual temperature measurement value fed back by the second temperature sensor 4, according to the existing data mapping table, and quickly responds to and controls the working state of the second thermoelectric cooler 3, thereby achieving precise control of the temperature of the laser diode 6.

[0042] In actual operation, the microprocessor first activates the first-stage thermoelectric cooler TEC hot-end temperature control unit to stabilize the hot-end temperature of the second thermoelectric cooler 3 at a preset value, such as 15±0.1°C. Then, it activates the second-stage laser diode temperature control unit to precisely control the temperature of the laser diode 6 at the operating temperature, such as 10±0.005°C.

[0043] Features of digital PID controllers:

[0044] 1. High flexibility: Parameters are easy to adjust, enabling complex control.

[0045] 2. High adaptability: It can achieve adaptive parameter adjustment and automatically optimize according to the working status.

[0046] 3. Quantization noise exists: Due to the quantization error introduced during the A / D conversion process, the accuracy is limited by the resolution.

[0047] 4. Sampling delay exists: The control response has a certain time delay, typically on the order of milliseconds.

[0048] 5. Good anti-interference ability: Digital systems have strong resistance to electromagnetic interference and noise.

[0049] Characteristics of analog PID controllers:

[0050] 1. Fast response speed: no sampling delay, almost real-time control.

[0051] 2. Inherently low noise: No quantization error, good linearity, and can achieve ultra-high precision control.

[0052] 3. Continuous control: Signal processing is continuous throughout, with no discretization error.

[0053] 4. Functional limitations: It is difficult to implement complex control and adaptive functions.

[0054] 5. Fixed parameters: Parameter adjustment requires physical replacement of components, making it difficult to adjust frequently.

[0055] The optimal combination is a first-stage digital PID controller plus a second-stage analog PID controller, as explained below.

[0056] 1. The first-stage digital PID controller provides flexibility, adaptability, and rich functionality, enabling it to effectively respond to environmental changes.

[0057] 2. The second-stage analog PID controller provides noiseless, fast-response, and precise control, ensuring extremely high temperature stability of the LD.

[0058] 3. This combination fully leverages the technological advantages of each component while mitigating their respective limitations.

[0059] The technical solution of this application is used for laser diode temperature control. It is a high-precision laser diode temperature control device with two-stage hybrid PID control. It is also suitable for optical systems with stringent requirements for wavelength stability, such as fiber optic sensors and laser interferometers.

[0060] Therefore, achieving a laser diode temperature control system with higher precision, higher stability, and lower power consumption enables laser diodes to meet the stringent requirements of modern high-precision optoelectronic systems and expands their application range.

[0061] Innovation points:

[0062] 1. A cascaded thermoelectric cooler (TEC) structure is adopted to form a new temperature control architecture in the temperature control device. The first-stage thermoelectric cooler (TEC) controls the hot end temperature of the second-stage thermoelectric cooler (TEC), creating a stable thermal environment for the second-stage thermoelectric cooler (TEC) and improving the temperature control accuracy.

[0063] 2. The control concept of independent but coordinated operation between the first-stage thermoelectric cooler (TEC) hot-end temperature control and the second-stage laser diode temperature control avoids the problem of limited control accuracy caused by the mutual coupling of hot and cold end temperatures in traditional single-stage systems.

[0064] 3. The hybrid PID control strategy fully leverages the strong adaptability of digital PID and the low noise and fast response characteristics of analog PID, effectively solving the problem that a single control method cannot simultaneously achieve system stability, precise control, and fast response.

[0065] 4. A dedicated heat conduction optimization structure was designed to ensure efficient and controllable heat conduction between the two-stage systems, thereby improving the overall system's temperature stability and control accuracy.

[0066] Compared with existing technologies, the two-stage hybrid PID control temperature control device formed by the microprocessor, the primary thermoelectric cooler (TEC) hot-end temperature control unit, and the secondary laser diode temperature control unit in this application has achieved significant improvements and technological advancements, realizing high temperature control accuracy and good stability.

[0067] Based on this, the introduction of radiator 5 can further improve the temperature control accuracy and stability.

[0068] Based on this, the introduction of insulation layer 7 can further improve the temperature control accuracy and stability.

[0069] Compared to the above embodiments, temperature sensor measurement can also employ a non-contact temperature measurement structure, thus achieving non-contact temperature measurement.

Claims

1. A temperature control device with two-stage hybrid PID control, characterized in that: The system includes a microprocessor, a first thermoelectric cooler (1), a first temperature sensor (2), a digital PID controller, a second thermoelectric cooler (3), a second temperature sensor (4), and an analog PID controller. The hot end of the second thermoelectric cooler (3) is in contact with and connected to the cold end of the first thermoelectric cooler (1). The cold end of the second thermoelectric cooler (3) is used to contact and connect with the laser diode. The microprocessor is electrically connected to the digital PID controller and the analog PID controller. The first temperature sensor (2) is electrically connected to the digital PID controller and the digital PID controller is electrically connected to the first thermoelectric cooler (1). The second temperature sensor (4) is electrically connected to the analog PID controller and the analog PID controller is electrically connected to the second thermoelectric cooler (3). The first temperature sensor (2) is used to monitor and obtain the temperature of the hot end of the second thermoelectric cooler (3) and inform the digital PID controller. The second temperature sensor (4) is used to monitor and obtain the temperature of the laser diode and inform the analog PID controller.

2. The temperature control device with two-stage hybrid PID control according to claim 1, characterized in that: The first temperature sensor (2) is in contact with and fixedly connected to the hot end of the second thermoelectric cooler (3).

3. The temperature control device with two-stage hybrid PID control according to claim 1, characterized in that: The second temperature sensor (4) is used to contact and be fixedly connected to the laser diode.

4. The temperature control device with two-stage hybrid PID control according to claim 1, characterized in that: It also includes a radiator (5) that connects the hot end of the first thermoelectric cooler (1) to the radiator (5).

5. The temperature control device with two-stage hybrid PID control according to claim 1, characterized in that: It also includes a laser diode (6), the cold end of the second thermoelectric cooler (3) is contacted and connected to the laser diode (6), and the second temperature sensor (4) is contacted and connected to the laser diode (6).

6. The temperature control device with two-stage hybrid PID control according to claim 1, characterized in that: It also includes a thermal insulation layer (7), which covers and fixes the first thermoelectric cooler (1), the first temperature sensor (2), the second thermoelectric cooler (3), and the second temperature sensor (4).

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